From: Yannick Fertré <yannick.fertre@st.com>
Date: Wed, 3 Apr 2019 09:24:13 +0000 (+0200)
Subject: drm/stm: ltdc: reset controller to avoid partial refresh
X-Git-Tag: v5.3-rc1~81^2~27^2~112
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=f42f540b9d0c16ffc0dd15a2d5c5f837bb7441c2;p=linux.git

drm/stm: ltdc: reset controller to avoid partial refresh

Display controller reset must be done as soon as possible after enable
the clock to avoid partial refresh on screen.

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1554283453-2879-1-git-send-email-yannick.fertre@st.com
---

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 17438c28d9fc..21a821ee065a 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1137,6 +1137,12 @@ int ltdc_load(struct drm_device *ddev)
 		return -ENODEV;
 	}
 
+	if (!IS_ERR(rstc)) {
+		reset_control_assert(rstc);
+		usleep_range(10, 20);
+		reset_control_deassert(rstc);
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ldev->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ldev->regs)) {
@@ -1163,11 +1169,6 @@ int ltdc_load(struct drm_device *ddev)
 		}
 	}
 
-	if (!IS_ERR(rstc)) {
-		reset_control_assert(rstc);
-		usleep_range(10, 20);
-		reset_control_deassert(rstc);
-	}
 
 	ret = ltdc_get_caps(ddev);
 	if (ret) {